DESCRIPTION: Despite the impressive economic progress in India, coverage for primary childhood vaccinations is abysmally low in urban slum communities. Vaccinations are not available to more than one third, and less than 40% of young children are fully vaccinated. The Indian Academy of Pediatrics (IAP) as other national and international pediatric bodies, recommends a time sensitive schedule for childhood immunizations, boosting immunity with each subsequent cycle, leading to adequate levels of immune protection. However, a major concern is the progressive decline in subsequent immunizations (after the first round), largely attributable to poor follow-up and compliance. Due to inadequate protective immunity, resulting from poor vaccination compliance, outbreak of vaccine-preventable diseases are rampant, making childhood mortality in this group among the highest in the world. Major challenges of vaccination programs include maintaining / tracking records, linked to positive identification of individual children, and efficiently connecting target populations with vaccines. Since urban-slums are nests inside sprawling cities, and cell-phone costs have decreased dramatically, there has been a rapid proliferation of cell-phone connectivity. Novel cellular technology based approaches for timely immunization reminder, can therefore significantly impact health outcomes in these communities. Our central hypothesis is that a web-based, biometric-linked vaccination record and timely vaccine reminders utilizing available cell-phone connectivity will provide robust and universal access of childhood vaccination records, efficiently connect target populations with vaccines, and cost-effectively increase primary childhood vaccination coverage. In this proposal, we will evaluate such a software platform in mother- infant units in urban-slum communities to improve uptake and coverage of primary childhood vaccinations in the developing world. We will build on an ongoing Indo-US collaboration with a Non- Governmental Organization (NGO) - Bal Umang Drishya Sanstha (BUDS) and a private Software Company - Royal Datamatics Pvt. Ltd. (RDPL), both operating locally in Delhi, India. BUDS is a non-profit organization led by a US trained Pediatrician - Dr. Rajeev Seth, and focuses on child health in several urban-slum communities in Delhi. RDPL is a renowned Indian software company with more than 10 years' experience in implementing integrated solutions. Our existing collaborations and public-private partnership will significantly defray costs, provide added value, and allow us to conduct this study, in vulnerable populations, with the limited resources available through this R03 funding mechanism.